[stefanha]

Can you be specific about what cannot be configured on mounted embedded media?

systemd follows the drop-in config file model where configuration snippets are placed into directories (like .d/ directories in Debian). It should not be necessary to run utilities from the target system in order to configure it on mounted media.

Drop unit files for services, sockets, filesystem mounts, timers, etc onto the mounted media and they will be detected when the target system boots.